Mahendra Singh DhoniMS Dhoni doesn't need any words on why he should be included in the playing XI. Infact he cannot be replaced by anyone, afterall he is the skipper of the team. His captaincy was criticized in the test series but his batting was impressive as he was the second highest scorer for India.
If Dhoni is replaced, one needs to find a batsman, a wicket keeper and a skipper which means he himself is a combination of 3 players. He is the only Indian skipper who has all the major ICC titles in his pocket. He led the team to victory in last year's Champions Trophy in England.
However if Dhoni is injured, Sanju Samson is the only option left to replace him.